Vacuum pump



FIG. 1 is a front elevational view of the vacuum pump showing my design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a top view thereof; and,

FIG. 6 is a bottom view thereof.

The areas that include the + and − sign and small circle shown in FIGS. 1 and 5 are slightly recessed from the overall surface. 

I claim the ornamental design for a vacuum pump, as shown and described. 